The enzymes involved in fungal cell wall biogenesis are attractive targets for antifungal intervention. These enzymes are unique to fungi and therefore provide highly selective antifungal targets. Furthermore, disruption of cell wall synthesis generally leads to a fungicidal response due to cell lysis induced by the osmotic instability of cells lacking an intact wall. Major structural components of fungal cell walls are β(1,3)-linked D-glucan polymers. These polymers are generated by β(1,3)-D-glucan synthase, an integral membrane protein complex that is required for fungal cell viability. Compounds described as inhibitors of glucan synthase have been described previously. Reference is made to Károlyházy, László et al. Arzneim.-Forsch./Drug Res. 2003, Vol. 53, No. 10, 738-743, which discloses 3-(2H)-pyridazinones of the formula:
where the various elements are defined therein. An illustrative compound of that series is:
Reference is made to Kondoh, Osamu et al., Biol. Pharm. Bull. 2005, 28, 2138-2141, which discloses piperazine propanol derivatives. An illustrative compound of that series is:
Reference is made to Brayman, Timothy et al., Antimicrobial Agents and Chemotherapy 2003 Vol. 47, No. 10, 3305-3310, which discloses the use of several compounds identified as glucan synthase inhibitors to test an assay for antifungal activity of glucan synthase inhibitors that uses germ tube formation in Candida albicans as an end point. An illustrative compound used to test the assay is:
Reference is made to Gomez, Gil et al., ES 540813 1985, which discloses 1,2-diazin-3(2H)-ones as compounds of pharmaceutical interest useful as antihypertensives, β-adrenergic blockers, antiulcer agents or as intermediates thereof. An illustrative compound of that series is:

Reference is made to Pauline C. Ting and Scott S. Walker, “New Agents to Treat Life-Threatening Fungal Infections” in Current Topics in Medicinal Chemistry, 2008, which discloses Antifungals that are inhibitors of glucan synthase. These antifungals include cyclic hexapeptides that are either approved for antifungal chemotherapy (caspofungin, micafungin anidulafungin) or under clinical development (aminocandin).